Synthesis gas, hydrogen and carbon monoxide, useful as feed to Fischer-Tropsch processes is often formed by steam reforming or partial oxidation of materials such as methane, natural gas, lower hydrocarbons, coal, and the like all of which often contain nitrogen in various forms. Oxygen, as such, or air can be used in either process and leads to the presence of nitrogen in the feed to the synthesis gas plant. The presence of nitrogen in the feeds to a synthesis gas generation process often results in HCN in the synthesis gas product. (Air plants for the separation of oxygen and nitrogen are not 100% efficient.) HCN is a poison for Fischer-Tropsch processes, particularly those utilizing Group VIII metal catalysts. Catalyst activity is thus reduced, and while activity may be regained by hydrogen treatment, the interruption of the process and treatment step are economic debits for the process.
While processes exist for HCN removal, these processes are not generally capable of removing the 90+% of HCN necessary for viable Fischer-Tropsch processing and do not operate at the relatively low Fischer-Tropsch reaction temperatures, also resulting in economic debits for the process. Also, HCN is only weakly soluble in water or normal solvents and water scrubbing or gas scrubbing of the HCN containing synthesis gas is not economically attractive for further use of the gas in Fischer-Tropsch synthesis.